Subject: Re: [PATCH v4 4/6] usb: dwc3: qcom: Add support for booting with ACPI

From: Lee Jones <[email-masked]>
Date: Mon, 17 Jun 2019 11:21:46 +0100

Felipe,

> In Linux, the DWC3 core exists as its own independent platform device.
> Thus when describing relationships in Device Tree, the current default
> boot configuration table option, the DWC3 core often resides as a child
> of the platform specific node.  Both of which are given their own
> address space descriptions and the drivers can be mostly agnostic to
> each other.
> 
> However, other Operating Systems have taken a more monolithic approach,
> which is evident in the configuration ACPI tables for the Qualcomm
> Snapdragon SDM850, where all DWC3 (core and platform) components are
> described under a single IO memory region.
> 
> To ensure successful booting using the supplied ACPI tables, we need to
> devise a way to chop up the address regions provided and subsequently
> register the DWC3 core with the resultant information, which is
> precisely what this patch aims to achieve.
> 
> Signed-off-by: Lee Jones <[email-masked]>
> Reviewed-by: Bjorn Andersson <[email-masked]>
> ---
>  drivers/usb/dwc3/Kconfig     |   2 +-
>  drivers/usb/dwc3/dwc3-qcom.c | 206 ++++++++++++++++++++++++++++++-----
>  2 files changed, 179 insertions(+), 29 deletions(-)

I'm starting to get a little twitchy about these patches now.  Due to
the release cadence of the larger Linux distros, it's pretty important
that these changes land in v5.3.  Without them, it is impossible to
install Linux on some pretty high profile emerging platforms.

It's already -rc5 and I'm concerned that we're going to miss the
merge-window.  Would you be kind enough to review these patches
please?  The Pinctrl and I2C parts of the set have already been
merged.

TIA.

> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 2b1494460d0c..6dab3fd1e233 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -116,7 +116,7 @@ config USB_DWC3_ST
>  config USB_DWC3_QCOM
>  	tristate "Qualcomm Platform"
>  	depends on EXTCON && (ARCH_QCOM || COMPILE_TEST)
> -	depends on OF
> +	depends on (OF || ACPI)
>  	default USB_DWC3
>  	help
>  	  Some Qualcomm SoCs use DesignWare Core IP for USB2/3
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 184df4daa590..1e1f12b7991d 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -4,6 +4,7 @@
>   * Inspired by dwc3-of-simple.c
>   */
>  
> +#include <linux/acpi.h>
>  #include <linux/io.h>
>  #include <linux/of.h>
>  #include <linux/clk.h>
> @@ -38,6 +39,20 @@
>  #define PWR_EVNT_LPM_IN_L2_MASK			BIT(4)
>  #define PWR_EVNT_LPM_OUT_L2_MASK		BIT(5)
>  
> +#define SDM845_QSCRATCH_BASE_OFFSET		0xf8800
> +#define SDM845_QSCRATCH_SIZE			0x400
> +#define SDM845_DWC3_CORE_SIZE			0xcd00
> +
> +struct dwc3_acpi_pdata {
> +	u32			qscratch_base_offset;
> +	u32			qscratch_base_size;
> +	u32			dwc3_core_base_size;
> +	int			hs_phy_irq_index;
> +	int			dp_hs_phy_irq_index;
> +	int			dm_hs_phy_irq_index;
> +	int			ss_phy_irq_index;
> +};
> +
>  struct dwc3_qcom {
>  	struct device		*dev;
>  	void __iomem		*qscratch_base;
> @@ -56,6 +71,8 @@ struct dwc3_qcom {
>  	struct notifier_block	vbus_nb;
>  	struct notifier_block	host_nb;
>  
> +	const struct dwc3_acpi_pdata *acpi_pdata;
> +
>  	enum usb_dr_mode	mode;
>  	bool			is_suspended;
>  	bool			pm_suspended;
> @@ -300,12 +317,27 @@ static void dwc3_qcom_select_utmi_clk(struct dwc3_qcom *qcom)
>  			  PIPE_UTMI_CLK_DIS);
>  }
>  
> +static int dwc3_qcom_get_irq(struct platform_device *pdev,
> +			     const char *name, int num)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	int ret;
> +
> +	if (np)
> +		ret = platform_get_irq_byname(pdev, name);
> +	else
> +		ret = platform_get_irq(pdev, num);
> +
> +	return ret;
> +}
> +
>  static int dwc3_qcom_setup_irq(struct platform_device *pdev)
>  {
>  	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
> +	const struct dwc3_acpi_pdata *pdata = qcom->acpi_pdata;
>  	int irq, ret;
> -
> -	irq = platform_get_irq_byname(pdev, "hs_phy_irq");
> +	irq = dwc3_qcom_get_irq(pdev, "hs_phy_irq",
> +				pdata ? pdata->hs_phy_irq_index : -1);
>  	if (irq > 0) {
>  		/* Keep wakeup interrupts disabled until suspend */
>  		irq_set_status_flags(irq, IRQ_NOAUTOEN);
> @@ -320,7 +352,8 @@ static int dwc3_qcom_setup_irq(struct platform_device *pdev)
>  		qcom->hs_phy_irq = irq;
>  	}
>  
> -	irq = platform_get_irq_byname(pdev, "dp_hs_phy_irq");
> +	irq = dwc3_qcom_get_irq(pdev, "dp_hs_phy_irq",
> +				pdata ? pdata->dp_hs_phy_irq_index : -1);
>  	if (irq > 0) {
>  		irq_set_status_flags(irq, IRQ_NOAUTOEN);
>  		ret = devm_request_threaded_irq(qcom->dev, irq, NULL,
> @@ -334,7 +367,8 @@ static int dwc3_qcom_setup_irq(struct platform_device *pdev)
>  		qcom->dp_hs_phy_irq = irq;
>  	}
>  
> -	irq = platform_get_irq_byname(pdev, "dm_hs_phy_irq");
> +	irq = dwc3_qcom_get_irq(pdev, "dm_hs_phy_irq",
> +				pdata ? pdata->dm_hs_phy_irq_index : -1);
>  	if (irq > 0) {
>  		irq_set_status_flags(irq, IRQ_NOAUTOEN);
>  		ret = devm_request_threaded_irq(qcom->dev, irq, NULL,
> @@ -348,7 +382,8 @@ static int dwc3_qcom_setup_irq(struct platform_device *pdev)
>  		qcom->dm_hs_phy_irq = irq;
>  	}
>  
> -	irq = platform_get_irq_byname(pdev, "ss_phy_irq");
> +	irq = dwc3_qcom_get_irq(pdev, "ss_phy_irq",
> +				pdata ? pdata->ss_phy_irq_index : -1);
>  	if (irq > 0) {
>  		irq_set_status_flags(irq, IRQ_NOAUTOEN);
>  		ret = devm_request_threaded_irq(qcom->dev, irq, NULL,
> @@ -371,11 +406,11 @@ static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
>  	struct device_node	*np = dev->of_node;
>  	int			i;
>  
> -	qcom->num_clocks = count;
> -
> -	if (!count)
> +	if (!np || !count)
>  		return 0;
>  
> +	qcom->num_clocks = count;
> +
>  	qcom->clks = devm_kcalloc(dev, qcom->num_clocks,
>  				  sizeof(struct clk *), GFP_KERNEL);
>  	if (!qcom->clks)
> @@ -409,12 +444,103 @@ static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
>  	return 0;
>  }
>  
> -static int dwc3_qcom_probe(struct platform_device *pdev)
> +static int dwc3_qcom_acpi_register_core(struct platform_device *pdev)
>  {
> +	struct dwc3_qcom 	*qcom = platform_get_drvdata(pdev);
> +	struct device		*dev = &pdev->dev;
> +	struct resource		*res, *child_res = NULL;
> +	int			irq;
> +	int			ret;
> +
> +	qcom->dwc3 = platform_device_alloc("dwc3", PLATFORM_DEVID_AUTO);
> +	if (!qcom->dwc3)
> +		return -ENOMEM;
> +
> +	qcom->dwc3->dev.parent = dev;
> +	qcom->dwc3->dev.type = dev->type;
> +	qcom->dwc3->dev.dma_mask = dev->dma_mask;
> +	qcom->dwc3->dev.dma_parms = dev->dma_parms;
> +	qcom->dwc3->dev.coherent_dma_mask = dev->coherent_dma_mask;
> +
> +	child_res = kcalloc(2, sizeof(*child_res), GFP_KERNEL);
> +	if (!child_res)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(&pdev->dev, "failed to get memory resource\n");
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	child_res[0].flags = res->flags;
> +	child_res[0].start = res->start;
> +	child_res[0].end = child_res[0].start +
> +		qcom->acpi_pdata->dwc3_core_base_size;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	child_res[1].flags = IORESOURCE_IRQ;
> +	child_res[1].start = child_res[1].end = irq;
> +
> +	ret = platform_device_add_resources(qcom->dwc3, child_res, 2);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to add resources\n");
> +		goto out;
> +	}
> +
> +	ret = platform_device_add(qcom->dwc3);
> +	if (ret)
> +		dev_err(&pdev->dev, "failed to add device\n");
> +
> +out:
> +	kfree(child_res);
> +	return ret;
> +}
> +
> +static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> +{
> +	struct dwc3_qcom 	*qcom = platform_get_drvdata(pdev);
>  	struct device_node	*np = pdev->dev.of_node, *dwc3_np;
>  	struct device		*dev = &pdev->dev;
> +	int			ret;
> +
> +	dwc3_np = of_get_child_by_name(np, "dwc3");
> +	if (!dwc3_np) {
> +		dev_err(dev, "failed to find dwc3 core child\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = of_platform_populate(np, NULL, NULL, dev);
> +	if (ret) {
> +		dev_err(dev, "failed to register dwc3 core - %d\n", ret);
> +		return ret;
> +	}
> +
> +	qcom->dwc3 = of_find_device_by_node(dwc3_np);
> +	if (!qcom->dwc3) {
> +		dev_err(dev, "failed to get dwc3 platform device\n");
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dwc3_acpi_pdata sdm845_acpi_pdata = {
> +	.qscratch_base_offset = SDM845_QSCRATCH_BASE_OFFSET,
> +	.qscratch_base_size = SDM845_QSCRATCH_SIZE,
> +	.dwc3_core_base_size = SDM845_DWC3_CORE_SIZE,
> +	.hs_phy_irq_index = 1,
> +	.dp_hs_phy_irq_index = 4,
> +	.dm_hs_phy_irq_index = 3,
> +	.ss_phy_irq_index = 2
> +};
> +
> +static int dwc3_qcom_probe(struct platform_device *pdev)
> +{
> +	struct device_node	*np = pdev->dev.of_node;
> +	struct device		*dev = &pdev->dev;
>  	struct dwc3_qcom	*qcom;
> -	struct resource		*res;
> +	struct resource		*res, *parent_res = NULL;
>  	int			ret, i;
>  	bool			ignore_pipe_clk;
>  
> @@ -425,6 +551,14 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, qcom);
>  	qcom->dev = &pdev->dev;
>  
> +	if (ACPI_HANDLE(dev)) {
> +		qcom->acpi_pdata = acpi_device_get_match_data(dev);
> +		if (!qcom->acpi_pdata) {
> +			dev_err(&pdev->dev, "no supporting ACPI device data\n");
> +			return -EINVAL;
> +		}
> +	}
> +
>  	qcom->resets = devm_reset_control_array_get_optional_exclusive(dev);
>  	if (IS_ERR(qcom->resets)) {
>  		ret = PTR_ERR(qcom->resets);
> @@ -454,7 +588,21 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	}
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	qcom->qscratch_base = devm_ioremap_resource(dev, res);
> +
> +	if (np) {
> +		parent_res = res;
> +	} else {
> +		parent_res = kmemdup(res, sizeof(struct resource), GFP_KERNEL);
> +		if (!parent_res)
> +			return -ENOMEM;
> +
> +		parent_res->start = res->start +
> +			qcom->acpi_pdata->qscratch_base_offset;
> +		parent_res->end = parent_res->start +
> +			qcom->acpi_pdata->qscratch_base_size;
> +	}
> +
> +	qcom->qscratch_base = devm_ioremap_resource(dev, parent_res);
>  	if (IS_ERR(qcom->qscratch_base)) {
>  		dev_err(dev, "failed to map qscratch, err=%d\n", ret);
>  		ret = PTR_ERR(qcom->qscratch_base);
> @@ -462,13 +610,8 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	}
>  
>  	ret = dwc3_qcom_setup_irq(pdev);
> -	if (ret)
> -		goto clk_disable;
> -
> -	dwc3_np = of_get_child_by_name(np, "dwc3");
> -	if (!dwc3_np) {
> -		dev_err(dev, "failed to find dwc3 core child\n");
> -		ret = -ENODEV;
> +	if (ret) {
> +		dev_err(dev, "failed to setup IRQs, err=%d\n", ret);
>  		goto clk_disable;
>  	}
>  
> @@ -481,16 +624,13 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	if (ignore_pipe_clk)
>  		dwc3_qcom_select_utmi_clk(qcom);
>  
> -	ret = of_platform_populate(np, NULL, NULL, dev);
> -	if (ret) {
> -		dev_err(dev, "failed to register dwc3 core - %d\n", ret);
> -		goto clk_disable;
> -	}
> +	if (np)
> +		ret = dwc3_qcom_of_register_core(pdev);
> +	else
> +		ret = dwc3_qcom_acpi_register_core(pdev);
>  
> -	qcom->dwc3 = of_find_device_by_node(dwc3_np);
> -	if (!qcom->dwc3) {
> -		dev_err(&pdev->dev, "failed to get dwc3 platform device\n");
> -		ret = -ENODEV;
> +	if (ret) {
> +		dev_err(dev, "failed to register DWC3 Core, err=%d\n", ret);
>  		goto depopulate;
>  	}
>  
> @@ -514,7 +654,10 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	return 0;
>  
>  depopulate:
> -	of_platform_depopulate(&pdev->dev);
> +	if (np)
> +		of_platform_depopulate(&pdev->dev);
> +	else
> +		platform_device_put(pdev);
>  clk_disable:
>  	for (i = qcom->num_clocks - 1; i >= 0; i--) {
>  		clk_disable_unprepare(qcom->clks[i]);
> @@ -601,6 +744,12 @@ static const struct of_device_id dwc3_qcom_of_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, dwc3_qcom_of_match);
>  
> +static const struct acpi_device_id dwc3_qcom_acpi_match[] = {
> +	{ "QCOM2430", (unsigned long)&sdm845_acpi_pdata },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(acpi, dwc3_qcom_acpi_match);
> +
>  static struct platform_driver dwc3_qcom_driver = {
>  	.probe		= dwc3_qcom_probe,
>  	.remove		= dwc3_qcom_remove,
> @@ -608,6 +757,7 @@ static struct platform_driver dwc3_qcom_driver = {
>  		.name	= "dwc3-qcom",
>  		.pm	= &dwc3_qcom_dev_pm_ops,
>  		.of_match_table	= dwc3_qcom_of_match,
> +		.acpi_match_table = ACPI_PTR(dwc3_qcom_acpi_match),
>  	},
>  };
>  

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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